I'm aware that the old school renaissance (OSR) is all about hearkening back to old versions of D&D and the play styles of the 70's and 80's, but what characteristics really define this movement? What minimum set of qualities does my game play require to be "old school"?

Play, write or referee one of the older editions of Dungeons and Dragon. Older edition meaning every version of AD&D/D&D prior to D&D 3.0. Although some will quibble on AD&D 2.0.

Some may talk about play styles but if you survey everybody that you could remotely include in the OSR. The only common thing you can say is that "They play older versions of D&D."

Also Old School Renaissance is an organic term that got accepted by the internet community as a way to describe the number of different groups playing older editions. There is no formal or loose organization. Some who play older editions vehemently deny they are a part of the OSR, others embrace it whole heartily, and some publishers use it as a marketing tool. Which is par for the course for this kind of meme.

To me the Old School Renaissance is
not about playing a particular set of
rules in a particular way, the dungeon
crawl. It about going back to the
roots of our hobby and see what we
could do differently. What avenues
were not explored because of the
commercial and personal interests of
the game designers of the time.

To me the single largest defining characteristic is DIY. This doesn't mean you don't buy modules or settings but that they are things to mine for creating your own world. I got involved in the OSR when it sparked my creative side and reminded me that there was a time when playing in Tom's D&D game was as different from playing in Harry's D&D game as playing Vampire is from playing Champions and both were that different from Dick's game.

I do like a lot of osr labeled works, but diy is a defining trait of gaming period.
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Mike FAug 29 '10 at 10:56

1

@AberrantHiveMind you would think, but some people only run published adventures... Hell, that's what Pathfinder's organized play is all about.
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AvioseAug 1 '14 at 15:43

@Aviose: Exactly. I think the OSR is to a large degree a specific reaction against that and the trend to design later D&D iterations to make reliance on approved material higher due to thinks like the balance fetish.
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HerbNAug 2 '14 at 16:28

Thanks for your personal perspective. I love how it encouraged you to contribute art you didn't think was high quality! Do you find there wasn't a community for "new school" D&D?
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Adam DrayAug 27 '10 at 21:13

Well, at the time there was Dungeon and Dragon magazine. The barrier to entry seemed incredibly high. Even Kobold Quarterly had wonderful art. But Fight On! Magazine had stuff that seemed doable. It had maps that I could have done. I felt that this magazine was made by people like me. Ordinary folks.
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Alex SchröderAug 27 '10 at 23:18

Means you can afford to buy your own pizza instead of having to share one. To me OSR is not about how many magic items you can collect, how much gold you can horde, but how long you can survive. It's more brutal that the heroic versions of D&D. The body count is higher. The rules are a skeletal structure for the GM to fill as he or she pleases.

OSR is something of a rolling definition. Since it kicked in after 3.5 when Mongoose demonstrated what could be done with the OGL, it started around there. It was basically take an edition, look at the previous one, skip it, and go one earlier. So at the start the OSR was AD&D 1e or earlier, and on the same line, B/X D&D or earlier (but not including BECMI). That was 70s and early 80s. Since 4th Edition was announced, several people (I think there are at least 3 separate projects) have started working on AD&D 2e, and BECMI/RC also got OSRed. Once 5th Edition comes out, there might be a D&D3e retro-clone, and Pathfinder will probably stick around as is.

That also shows that Old School is relative. Since I was born in 1984, AD&D 2e is about as early as it goes for me, since I probably wouldn't have started playing at 4 years old. Older people would naturally go back to their first edition, which would be either AD&D, or BD&D red/blue boxes.

There's also the Old School style games, like Stars Without Number, which aren't a specific retroclone, but are done in the old school style. I've noticed in general there wasn't a great deal of mechanical innovation from 1974 to 1989, with the biggest difference being an alternate dice system, and WEG's D6 system for Star Wars that had Mechanics as a stat, rather than just a base attribute was about as forward thinking as it got. Starting with the 90s, there was significantly more innovation kicking in, going as far as Everway doing away with numeric stats altogether. That decade though is still rather significant in that it happened before the craze for a unified mechanic came about (obviously this was building up in earlier systems, but it seems d20 really shifted it in that direction).

Right now I've only seen old school style games identified as such if they come from the first 15 years, but I would be surprised to see 90s style games included in that in the near future as well. At this point 10-20 years old instead of 20-35 years old is still a significant leap back.